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Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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Face (par) amount of debt instrument at time of issuance.

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Incremental percentage increase (decrease) in the stated rate on a debt instrument.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Weighted average interest rate of debt outstanding.

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Cap rate on an interest rate derivative such as an interest rate cap or collar. If market rates exceed the cap rate, a payment or receipt is triggered on the contract.

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Amount of liability hedged in fair value hedging relationship.

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Amount of the cost of borrowed funds accounted for as interest expense for debt.

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Amount of cash paid for interest, including, but not limited to, capitalized interest and payment to settle zero-coupon bond attributable to accreted interest of debt discount and debt instrument with insignificant coupon interest rate in relation to effective interest rate of borrowing attributable to accreted interest of debt discount; classified as operating and investing activities.

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Amount of current borrowing capacity under the credit facility considering any current restrictions on the amount that could be borrowed (for example, borrowings may be limited by the amount of current assets), but without considering any amounts currently outstanding under the facility.

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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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The cash inflow during the period from additional borrowings in aggregate debt. Includes proceeds from short-term and long-term debt.

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Amount of cash outflow for payment of an obligation from a lender, including but not limited to, letter of credit, standby letter of credit and revolving credit arrangements.

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Debt - Narrative (Details) £ in Millions					12 Months Ended
Debt - Narrative (Details) £ in Millions	Apr. 07, 2020 USD ($)	Apr. 07, 2020 GBP (£)	Apr. 01, 2019 USD ($)	May 11, 2018 USD ($)	Dec. 31, 2020 USD ($) credit_facility	Dec. 31, 2020 GBP (£)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Jun. 15, 2018 USD ($)	May 18, 2018 USD ($)
Debt Instrument
Total commitment under revolving credit facility	$ 291,400,000
Debt					$ 376,400,000		$ 283,500,000
Secured credit facilities \| credit_facility					2
Interest expense					$ 29,500,000		17,600,000	$ 9,500,000
Interest paid					27,000,000.0		16,300,000	8,800,000
First Credit Facility
Debt Instrument
Total commitment under revolving credit facility					16,300,000
Second Credit Facility
Debt Instrument
Total commitment under revolving credit facility					15,000,000.0
NSM
Debt Instrument
Debt instrument at face value				$ 100,000,000.0
Debt					272,600,000		219,200,000
NSM \| NSM Bank Facility
Debt Instrument
Total commitment under revolving credit facility				234,000,000.0
Debt instrument at face value					$ 277,400,000
Percentage of discounted future cash flows					10.00%	10.00%
Debt					$ 277,400,000		221,300,000	180,400,000
Kudu \| Kudu Debt
Debt Instrument
Total commitment under revolving credit facility					124,000,000.0
Term Loan \| First Credit Facility
Debt Instrument
Total commitment under revolving credit facility					11,300,000
Long-term debt, gross					9,100,000
Term Loan \| Second Credit Facility
Debt Instrument
Total commitment under revolving credit facility					9,000,000.0
Long-term debt, gross					8,900,000
Term Loan \| NSM \| NSM Bank Facility
Debt Instrument
Total commitment under revolving credit facility				224,000,000.0
Debt instrument at face value	276,400,000				277,400,000		221,300,000			$ 51,000,000.0
Proceeds from borrowings	52,400,000	£ 42.5			52,400,000	£ 42.5	42,900,000
Debt					271,300,000		217,400,000
Term Loan \| NSM \| Other NSM
Debt Instrument
Debt instrument at face value					1,300,000
Debt					1,300,000		1,800,000
Term Loan \| Kudu \| Kudu Debt
Debt Instrument
Total commitment under revolving credit facility					57,000,000.0
Debt instrument at face value					89,200,000		57,000,000.0
Delayed Draw Term Loans \| First Credit Facility
Debt Instrument
Total commitment under revolving credit facility					3,000,000.0
Delayed Draw Term Loans \| Second Credit Facility
Debt Instrument
Total commitment under revolving credit facility					4,000,000.0
Delayed Draw Term Loans \| Kudu \| Kudu Debt
Debt Instrument
Total commitment under revolving credit facility					62,000,000.0
Revolving Credit Facility \| First Credit Facility
Debt Instrument
Total commitment under revolving credit facility					2,000,000.0
Repayments of Lines of Credit					2,000,000.0		200,000
Revolving Credit Facility \| Second Credit Facility
Debt Instrument
Total commitment under revolving credit facility					2,000,000.0
Repayments of Lines of Credit					100,000
Revolving Credit Facility \| NSM \| NSM Bank Facility
Debt Instrument
Total commitment under revolving credit facility	$ 15,000,000.0			$ 10,000,000.0
Proceeds from borrowings					0		6,500,000
Revolving Credit Facility \| Kudu \| Kudu Debt
Debt Instrument
Total commitment under revolving credit facility					5,000,000.0
Current borrowing capacity					$ 32,200,000		57,000,000.0
London Interbank Offered Rate (LIBOR) \| Line of Credit \| Kudu \| Kudu Debt
Debt Instrument
Basis spread on variable rate					1.00%	1.00%
London Interbank Offered Rate (LIBOR) \| Line of Credit \| Minimum \| Kudu \| Kudu Debt
Debt Instrument
Basis spread on variable rate					5.50%	5.50%
London Interbank Offered Rate (LIBOR) \| Line of Credit \| Maximum \| Kudu \| Kudu Debt
Debt Instrument
Basis spread on variable rate					6.25%	6.25%
British Sterling Pound London Interbank Offered Rate LIBOR \| Term Loan \| Minimum \| NSM \| NSM Bank Facility
Debt Instrument
Basis spread on variable rate					6.00%	6.00%
British Sterling Pound London Interbank Offered Rate LIBOR \| Term Loan \| Maximum \| NSM \| NSM Bank Facility
Debt Instrument
Basis spread on variable rate					6.50%	6.50%
Derivative, cap interest rate					1.25%
Prime Rate \| Line of Credit \| Kudu \| Kudu Debt
Debt Instrument
Basis spread on variable rate					1.00%	1.00%
Prime Rate \| Line of Credit \| Minimum \| Kudu \| Kudu Debt
Debt Instrument
Basis spread on variable rate					4.50%	4.50%
Prime Rate \| Line of Credit \| Maximum \| Kudu \| Kudu Debt
Debt Instrument
Basis spread on variable rate					5.25%	5.25%
United States Dollar London Interbank Offered Rate LIBOR \| Term Loan \| Minimum \| NSM \| NSM Bank Facility
Debt Instrument
Basis spread on variable rate				4.25%	5.50%	5.50%
United States Dollar London Interbank Offered Rate LIBOR \| Term Loan \| Maximum \| NSM \| NSM Bank Facility
Debt Instrument
Debt instrument, interest rate					1.25%	1.25%
Basis spread on variable rate				4.75%	6.00%	6.00%
Foreign Exchange Spot Rate \| Term Loan \| NSM \| NSM Bank Facility
Debt Instrument
Proceeds from borrowings					$ 58,100,000
Interest Rate Swap \| NSM \| NSM Bank Facility
Debt Instrument
Debt, weighted average interest rate					8.40%
Interest Rate Swap \| Term Loan \| NSM \| NSM Bank Facility
Debt Instrument
Total commitment under revolving credit facility					$ 151,000,000.0
Hedged liability, fair value hedge									$ 151,000,000.0
Debt					$ 147,600,000
Interest Rate Cap \| London Interbank Offered Rate (LIBOR) \| NSM
Debt Instrument
Derivative, cap interest rate					1.25%
Embrace Pet Insurance \| NSM
Debt Instrument
Proceeds from borrowings			$ 20,400,000
Embrace Pet Insurance \| Term Loan \| NSM \| NSM Bank Facility
Debt Instrument
Proceeds from borrowings							20,400,000
NSM
Debt Instrument
Interest expense					$ 22,100,000		$ 16,700,000	$ 8,000,000.0
Designated as Hedging Instrument \| Term Loan \| NSM \| NSM Bank Facility
Debt Instrument
Debt, weighted average interest rate					7.60%
Designated as Hedging Instrument \| Interest Rate Swap \| Term Loan \| NSM \| NSM Bank Facility
Debt Instrument
Debt					$ 147,600,000
Debt, weighted average interest rate					9.00%
Not Designated as Hedging Instrument \| Interest Rate Swap \| Term Loan \| NSM \| NSM Bank Facility
Debt Instrument
Debt					$ 129,800,000